Oh, I didn't realize it was a Chef Mickey dinner-I thought breakfast! Honestly, I would probably drop it and try for a different day or lunchtime. Going from AK to Contemporary back to AK is going to take a long time! For Rivers of Light, are you going to have a Fastpass, standby, or dining? If you want a good view that will put you on the opposite end of the park from the entrance. You will need to "battle" all the crowds to get back out of the park and considering its day after Thanksgiving there will be plenty of crowds. Then you have to call an uber and wait for it to arrive. Then you are still looking at at least a 20 minute drive over. With dinnertime crowds, you could have a delay (I was thinking early morning may not have as much a delay). Eating and check could take some time, then another uber needs to be called, and get back to AK. Park closes at 10pm, so you have to be in line by that time. They will still let you in until park close, but you can't get in line afterwards.
Are you set on Chef Mickey for dinner? Remember there is Tusker House in AK, as well as Boma at AKL. As well as other excellent table service restaurants at both.